Lubricating oil injectors for petrol engines



March 13, 1962 v. FRANTSEVITCH LUBRICATING OIL INJECTORS FOR PETROL ENGINES Filed April 10, 1959 mvemor V5EVOLO0 FM/VrsEV/mv Mm gm Aifomcys United rates Patent @hfroe 3,024,781 Patented Mar. 13, 1952 3,024,781 LUBRICA'IING @lllb ENJECTURS FUR PETRGL ENGINES Vsevolod Frantsevitch, Brussels-Schaerbeek, lieigium Filed Apr. 149, i359, Ser. No. 8%,Sti0 Claims priority, application Belgium Apr. 11, 1958 4 Claims. (Ci. l23--1%) This invention relates to improvements in lubricating oil injectors for petrol engines, of the kind comprising a vessel of substantially uniform cross section whose interior is connected at one end by an inlet to a source of lubricating oil and at the other end by an outlet to the induction manifold of a petrol engine, a free piston or outlet valve slidable in the vessel biased by gravity toward the inlet end and an inlet valve member biased by gravity to close the inlet, the arrangement being such that the drop in pressure below atmospheric pressure, or vacuum, in the induction manifold when the engine is started will cause movement of th piston toward the outlet end of the vessel, and drawing of a predetermined quantity of oil through the inlet and past the inlet valve member into the vessel, the inlet valve member closing the inlet when the vacuum ceases or is isolated from it and the piston returning more slowly to the inlet end, a portion of said oil passing from the inlet side of the piston to the outlet side so that it will be ejected through the outlet into the induction manifold of the engine as a result of the vacuum caused by the next starting of the engine.

The applicant has noticed that this type of device worked irregularly, due to the gases accidentally or intentionally introduced into the lubricating liquid. Actually, as the expansion coefficient of gases is appreciably higher than that of liquids, the inevitable changes of temperature under a car bonnet cause, inside the vessel of the injector, a pressure which is suflicient to interfere with the return force of the piston and valve member when they are in the closing position. Consequently, it happens that the outlet of the injector vessel remains closed, despite the absence of vacuum in the inlet manifold of the engine.

One object of the present invention is to eliminate the abov drawback and make the working of the injector independent of the quantity of gas contained in the lubrieating liquid.

Another object of the invention is the possibility of controlling the flow of oil from the injector to the engine in dependence of temperatures taken at a given point of the engine.

According to the invention, these objects are attained by means of a gas chamber communicating with the vessel of the injector. This gas chamber is situated behind the outlet valve, in the direction of the circulation of the lubricating liquid. This gas chamber may be placed inside, and at th top of the vessel, or outside the vessel, in which case it is connected thereto by a pipe. The gas chamber may be in communication with the outside air, or not.

The invention will now be described with reference to the accompanying drawing, illustrating, by way of example, three preferred embodiments.

FIG. 1 is a sectional view of one embodiment, with an internal gas chamber.

FIG. 2 is a similar view of a second embodiment, with an internal gas chamber in communication with outside FIG. 3 is a similar view of a third embodiment, with an outside gas chamber under the influence of the temperature prevailing at a given point.

In these figures, identical reference numbers indicate identical parts.

In the embodiment represented by FIG. 1, the gas chamber is inside the vessel. The injector comprises a vessel 1 with an end cap 2 at its upper end. Inside the vessel are two valves which are partly under the action of gravity and partly under the action of the vacuum in the inlet manifold of the engine. These valves are the inlet valve 3 and the free piston or outlet valve 4 which presents passages 5 for the liquid. The vessel is in communication, by means of pipe 6 with a lubricating oil tank (not shown) and, by means of pipe 7, with the inlet manifold 8 of the engine. The outlet pipe 7 enters the vessel 1 for a certain distance, so that a gas chamber 16) is formed above the mouth h of pipe 7.

This injection device works as follows: as it is placed near the engine, the gases contained in the liquid Warm up when the engine is hot. As these gases expand, they press the valve members 3 and 4 firmly on their seatings; the valves open only after the gases in chamber 19 have cooled.

In the second embodiment, represented by FIG. 2, the gas chamber, also placed inside the vessel 1, is in communication with the outside air by means of the opening 11, which can be closed by a stopper 12..

With free outlet, i.e. when chamber It) is in communication with the outside air, the working of the apparatus is independent of the temperature and of the gases arriving with the liquid. When opening 11 is closed, the device works as in FIG. 1.

In the third embodiment, shown in FIG. 3, the injection device is fitted with an additional outside gas chamber 1 connected to vessel 1 by a pipe 13. If the chamber 14 is thermally insulated, it makes the injection apparatus independent of the gases arriving with the liquid. In the embodiment shown, however, the chamber is in thermal contact with a part which, by its variations of temperature, causes the stopping or starting of the ap paratus, viz. the exhaust pipe 15 of the internal combustion engine. The temperature of this exhaust pipe therefore regulates the working of the apparatus: when the pipe 15 is hot, the apparatus does not discharge lubricating oil; when the pipe is cold, the apparatus discharges lubricating oil into the induction manifold as soon as the engine is started.

Gas chamber 10 is thus a suitable means for controlling the movement of valve member 4. Its functioning is now further described by an example.

Since there is a communication between the chambers located on each side of valve members 3 and 4, the pressure on each side thereof is equal. It is assumed for the example that the engine has stopped which means that there is no vacuum in pipe 7. It is also stated that the complete example will relate to the embodiment shown in FIGURE 1.

The following symbols are adopted:

S is the surface of the upper face of member 4 which is equal to the surface area of the lower face.

S1 is the surface of the seat 9 of valve member 4.

V is the volume of valve member 4.

d is the specific gravity of the lubricating liquid.

P is the weight of valve member 4.

p is the pressure on both sides of member 4.

The forces acting on member 4 upwardly are Vd-i-pS The forces acting on member 4 downwardly are )P= P- P To arrive at the resulting forces downwardly, subtract (I) from (2):

P-l-SpslpVd-Sp=Ps1p-Vd (3) If Expression 3 is positive or if Psln Vd 3 the valve member will be biased downwardly.

Ps1p Vd the valve member 4 will be biased upwardly and will close the pipe 7. In the latter case, no lubricating liquid will be sucked up during the next starting of the engine.

Expressions 4 and 5 are true for all the embodiments (FIGS. 1 to 3).

The above example is now applied to each embodiment individually.

FIGURE 1 (the gas chamber 10 is clsed).1f the engine and the injector placed near the engine is still hot, i.e., if the engine has stopped recently, p will be high, and consequently Expression will be true. Pipe 7 remains closed and no liquid can be sucked up during the the next starting of the engine. However, if the engine is cold, p will be low (atmospheric pressure), and Expression 4 will become true. During the next starting of the engine, lubricating fluid will be sucked up, due to the vacuum in pipe 7. After starting the engine, valve member 4 will remain on seat 9 due to the vacuum in pipe 7. No liquid is sucked up.

FIGURE 2 (plug 12 remwved).-Pressure p is always low (atmospheric pressure), since there is a communication with the outer atmosphere, and Expression 4 is always true. Even if the engine is hot, member 4 will be biased downwardly and lubricating liquid will be sucked up during the next starting of the engine.

FIGURE 3 (gas chamber in communication with chamber 14 located on exhaust pipe 15 of engine) .If the exhaust pipe is hot, p will be high, and Expression 5 is true. The pipe 7 will remain closed even after stopping of the engine, i.e., even if there is no more vacuum in pipe 7. It will be opened as soon as Expression 5 becomes true, i.e., as soon as a pressure p which corresponds to the temperature of the exhaust pipe is sufficiently low to correspond to Expression 5.

While several embodiments of the lubricating oil injector have been illustrated and described, the invention is not limited thereto but contemplates such modifications or other embodiments as may occur to those skilled in the art.

What is claimed is:

1. A lubricating oil injector for petrol engines comprising a vessel of substantially uniform cross section, an oil inlet pipe at the lower base of said vessel and intended to be connected to an oil tank, an oil outlet pipe at the upper base of said vessel, protruding down into said vessel, the outside extremity thereof being intended to be connected to the induction manifold of a petrol engine, a free piston slidable within said vessel and biased by gravity toward the inlet pipe, a free inlet valve member under said piston biased by gravity to close the inlet pipe, and an abutment seat for said piston at the end of the outlet pipe inside the vessel, said abutment seat delimiting, together with the upper bas and the side wall of said vessel, a gas chamber in communication with the remainder of the interior volume of said vessel.

2. A lubricating oil injector as claimed in claim 1, wherein said gas chamber is also in communication with the outside air.

3. A lubricating oil injector as claimed in claim 1, further comprising an additional outside gas chamber connected to the gas chamber inside the vessel by means of a pipe, said outside gas chamber being intended to be in thermal contact with a part of the engine that is subject to variations in temperature.

4. A lubricating oil injector as claimed in claim 3, wherein said'additional outside chamber is in communication with the outside air.

References Cited in the file of this patent UNITED STATES PATENTS Howell Mar. 29, 1955 

